Can these seats be used in australia

Hi JOnwin, thank you for your enquiry, the Diono seats are NZ “S” Standard so cannot be used in Australia, I have added a link for seats that are suitable for use and are Australian Standard. We hope this helps. https://www.babyonthemove.co.nz/car-seat/shop-by-standard/as-nz-standard.  if you follow the link https://www.babyonthemove.co.nz/store-locations/ this will take you to our online store finder. Here you can find contact details for your nearest Baby On The Move Store 
 where one of our team experts will be happy to assist you in your product search and help answer any further questions you may have.